First Day Winter 2024. Winter 2024 starts on saturday, december 21st in the northern hemisphere, with the first day of winter being the shortest daylight day of the year with the earth's axis having reached its furthest tilt away from the sun and begins to change directiion back. In the northern hemisphere, it always occurs around december 21 or 22.
It marks the northern hemisphere’s shortest day (first day of winter) and southern hemisphere’s longest day (first day of summer). The winter solstice usually occurs around dec.